Thermally activated bleaching clay product for oil bleaching

ABSTRACT

A product, a method of producing and a method of using are disclosed. The product comprises attapulgite that has been thermally activated. The product may have a permeability in oil in the range of 0.04-3 darcy and may have a surface area of 45-140 m2/g. The method of producing may comprise thermally activating a material that includes attapulgite by heating the material at a temperature in the range of 300 to 900° C. The method of decolorizing may include contacting for a contact time an oil with the bleaching clay product that comprises attapulgite that has been thermally activated, and separating the bleaching clay product from the oil to recover a decolorized oil that has a lower red color than the oil had prior to the contacting, and removing phosphorus and metals for hydrotreated vegetable oil (HVO)/renewable diesel feedstock pretreatment.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of U.S. patent applicationSer. No. 17/379,383, filed Jul. 19, 2021.

TECHNICAL FIELD

The present disclosure generally relates to clay based products suitablefor the bleaching of oil, and more particularly, activated clay basedproducts for the bleaching of edible oil and non-edible oil, and forhydrotreated vegetable oil (HVO)/renewable diesel feedstock oilpretreatment.

BACKGROUND

Natural clays such as bentonite have been used as bleaching clays toremove color pigments/impurities from edible and non-edible oils. Someoils may have color that is undesirable to a consumer and may bebleached or decolorized to remove color pigments/impurities from the oilto obtain a desirable color of the oil.

Bleaching clays generally improve oil color by adsorbing color pigmentssuch as carotenoids that are present. A bleaching clay with the highestbleaching efficiency (smallest dosage of bleaching material needed toproduce a certain decolorization effect on a given amount of oil) isdesirable because it results in cost reductions for refiners of oil.Purchasing and carrying costs are reduced when a smaller amount of clayis required for the decolorization process. Moreover, less spentbleaching clay is generated, which minimizes the loss of entrainedbleached oil and spent bleaching clay disposal costs.

Natural clays are typically acid activated (processed through a chemicaltreatment such as contact with a mineral or organic acid) to improvetheir bleaching efficiency for decolorizing oils. Although acidactivation does not improve the bleaching efficiency of all naturalclays, activation of calcium bentonite with sulfuric acid has beenutilized to improve the bleaching efficiency of calcium bentonite fordecolorization of oil.

Bleaching clays with smaller particle sizes typically result in higherbleaching activity but lower throughput. Oil refiners, in choosing ableaching clay are typically forced to compromise between getting themost decolorization per amount of bleaching clay versus processingspeed.

U.S. Pat. No. 5,008,226, issued Apr. 16, 1991, (the '226 Patent)describes a process for making acid-activated bleaching earth fromcertain naturally occurring mixtures of calcium bentonite andattapulgite clay. The process involves treating such clay with lowlevels of activating acid which are mixed with the dried and groundclay, or spray dried from slurries containing the clay-acid mixture.Advantages include lower acid costs/unit mass of clay treated and lowerproduction costs. While the disclosure of the '226 Publication may bebeneficial, the disclosed bleaching composition still suffers fromissues related to the use of acid activation such as undesirable amountsof soluble metals in the bleaching composition that may be transferredinto the decolorized oil during processing. A better bleaching clay isdesired.

SUMMARY OF THE DISCLOSURE

In another aspect of the disclosure, a bleaching clay product isdisclosed, the bleaching clay product may comprise attapulgite that hasbeen thermally activated. The bleaching clay product may have: (a) apermeability in oil in the range of 0.04-3 darcy, or 0.04-0.19 darcy, or0.04-0.07 darcy, or 0.07-0.19 darcy, or 1-3 darcy, or 1.5-3 darcy; and(b) a surface area of 45-140 m²/g or 80-140 m²/g. In an embodiment, theattapulgite may be free of acid activation. In an embodiment, theattapulgite may be free of residual acid (acid-free). In an embodiment,the bleaching clay product may be free of acid activation. In anembodiment, the bleaching clay product may be free of residual acid(acid-free). In any one of the embodiments above, the bleaching clayproduct may have a bleaching efficiency for Lovibond red of 50%-99% at1-3 wt. % bleaching clay product to oil and a contact time of 1-30minutes for bleaching. In any one of the embodiments above, theattapulgite may be agglomerated (e.g., spray dried), with or without abinder, prior to thermal activation. In any one of the embodimentsabove, the bleaching clay product may have a permeability of 2-3 darcy,a bleaching efficiency for Lovibond red of 76-99%, and a porosity of76-85% or 70-85%. In any one of the embodiments above, the bleachingclay product may have a pore volume of 1-3 mL/g or 1-2 mL/g. In any oneof the embodiments above, the bleaching clay product may have no morethan 4 parts per million (ppm) soluble lead as measured by the FCC, andhas no more than 1 ppm arsenic as measured by FCC. In any one of theembodiments above, the bleaching clay product may have intrinsic poresin the range of 17-30 nanometers (nm) and/or inter pores in the range of2-32 microns.

In one aspect of the present disclosure, a method of producing ableaching clay product is disclosed. The method may comprise thermallyactivating a material that includes attapulgite by heating the materialat a temperature to produce a bleaching clay product, the temperature inthe range of 300 to 900° C. or 400 to 850° C., wherein the bleachingclay product has a permeability in oil in the range of 0.04-3 darcy, andmay have a surface area of 45-140 m²/g or 80-140 m²/g. In an embodiment,the bleaching clay product may have no more than 4 ppm soluble lead asmeasured by the Food Chemical Codex (FCC) and no more than 1 ppm arsenicas measured by the FCC. In any one of the embodiments above, theattapulgite may be agglomerated (e.g., spray dried), with or without abinder, prior to thermally activating. In any one of the embodimentsabove, the bleaching clay product may have a bleaching efficiency forLovibond red of 50% to 99% at 1-3 wt. % bleaching clay product to oiland a contact time of 4-8 minutes for bleaching. In any one of theembodiments above, the bleaching clay product may have intrinsic poresin the range of 17-30 nm and/or inter pores in the range of 2-32microns.

In yet another aspect of the disclosure, a method for decolorizing anoil is disclosed. The method may comprise contacting for a contact timean oil with a bleaching clay product comprising attapulgite, the contacttime in the range 4-8 minutes, wherein the attapulgite has beenthermally activated, and separating the bleaching clay product from theoil to recover a decolorized oil that has a lower red color than the oilhad prior to the contacting, wherein the bleaching clay product has apermeability in oil in the range of 0.04-3 darcy. In an embodiment, theoil may be an edible oil. In any one of the embodiments above, the oiland slurry may be combined into a slurry, the slurry 1-5 wt. % bleachingclay product to oil. In any one of the embodiments above, the bleachingclay product may have a surface area of 45-140 m²/g or 80-140 m²/g. Inany one of the embodiments above, the red color is a Lovibond red andthe bleaching clay product may have a bleaching efficiency of 50% to 99%for the Lovibond red. In any one of the embodiments above, theattapulgite has been agglomerated (e.g., spray dried), with or without abinder, prior to thermal activation. In any one of the embodimentsabove, the attapulgite that has been thermally activated may have aporosity of 70-85% and/or a pore volume of 1-2 mL/g. In any one of theembodiments above, the attapulgite that has been thermally activated mayhave a porosity of 79-85% and/or a pore volume of 1-2 mL/g. In any oneof the embodiments above, the bleaching clay product may have apermeability in oil in the range of 0.04-0.19 darcy or 0.04-0.07 darcyor 0.07-0.19 darcy, or 1.5-3 darcy or 2-3 darcy. In any one of theembodiments above, the bleaching clay product may have no more than 4ppm soluble lead or no more than 0.6 ppm soluble lead, as measured bythe FCC, and/or has no more than 1 ppm soluble arsenic or no more than0.06 ppm soluble arsenic as measured by the FCC. In any one of theembodiments above, the bleaching clay product may have intrinsic poresin the range of 17-30 nm and/or inter pores in the range of 2-32microns.

In an aspect of the disclosure, a product is disclosed. The product maycomprise attapulgite that has been thermally activated. The product mayhave: (a) a permeability in an oil in the range of 0.04-3 darcy; (b) asurface area of 45-140 m²/g or 80-140 m²/g; (c) a removal efficiency inthe oil for phosphorus of 50% to 100%; and (d) a removal efficiency inthe oil for a metal of 50% to 100%. The product and/or the attapulgitemay be acid-free or free of residual acid or free of acid activation,and the oil may comprise or is a feedstock oil for hydrotreatedvegetable oil (HVO) or renewable diesel. In an embodiment, the productor the attapulgite may have a permeability in the range of 0.04-0.07darcy or 0.04-0.19 darcy or 1-3 darcy or 1.5-3 darcy. In any one or moreof the product, embodiments or refinements above, the metal may be ormay include calcium, magnesium, potassium, copper, or iron. In any oneor more of the product, embodiments or refinements above, the productmay have a removal efficiency in the oil for peroxide of 50% to 100%and/or a removal efficiency in the oil for chlorophyll of 50% to 100%and/or a bleaching efficiency in the oil for Lovibond red of 65% to100%. In any one or more of the embodiments or refinements above, theproduct may have a removal efficiency in the oil for phosphorus of 50%to 100% that leaves less than 2 ppm phosphorus content in the oil. Inany one or more of the embodiments or refinements above, the product mayhave removal efficiency in the oil for the metal of 50% to 100% thatleaves less than 10 ppm total metal content in the oil. In any one ormore of the product, embodiments or refinements above, the attapulgitethat has been thermally activated has a porosity of 70-85% and/or a porevolume of 1-2 mL/g. In any one or more of the product, embodiments orrefinements above, the attapulgite that has been thermally activated mayhave a d₉₀ of 65-95 μm. In any one or more of the product, embodimentsor refinements above, the product may have intrinsic pores in the rangeof 17-30 nm and/or inter pores in the range of 2-32 microns.

In another aspect of the disclosure, a method for treating an oil isdisclosed. The method may comprise: contacting for a contact time theoil with a product comprising attapulgite, the contact time in the range4-35 minutes, wherein the attapulgite has been thermally activated,wherein the product is free of residual acid; and separating the productfrom the oil to recover a treated oil, wherein the treated oil has alower amount of phosphorus than the oil had prior to the contacting andhas a lower amount of a metal than the oil has prior to the contacting,wherein further the treated oil has less than 0.5 parts per million(ppm) of phosphorus and less than 0.5 ppm of the metal; wherein thebleaching clay product has a permeability in oil in the range of 0.04-3darcy, wherein the oil comprises a feedstock oil for hydrotreatedvegetable oil (HVO) or renewable diesel. In an embodiment, the metal mayinclude or may be calcium, magnesium, potassium, copper, or iron. In arefinement, the metal is calcium. In any one or more of the method,embodiments or refinements above, the treated oil has a lower amount ofperoxide than the oil had prior to the contacting, wherein further thetreated oil has 1-3 meq/kg peroxide value. In any one or more of themethod, embodiments or refinements above, the treated oil has a loweramount of chlorophyll than the oil had prior to the contacting, whereinfurther the treated oil has 0-0.1 parts per million (ppm) ofchlorophyll. In any one or more of the method, embodiments orrefinements above, the treated oil has a lower red color than the oilhad prior to the contacting. In a refinement, the red color is aLovibond red and the product has a bleaching efficiency of 50% to 99%for Lovibond red. In any one or more of the method, embodiments orrefinements above, the product may have a permeability in oil in therange of 0.04-0.19 darcy or 1.5-3 darcy or 2-3 darcy. In any one or moreof the method, embodiments or refinements above, the contacting may beat a temperature of 80-125° C.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph of the X-ray diffraction (XRD) patterns of (1)attapulgite that has not been thermally activated (Acti-Gel 208®) and(2) attapulgite (Acti-Gel 208®) that has been thermally activated byheating at 700° C.;

FIG. 2 is a graph showing the pore size distribution of Acti-Gel 208(natural attapulgite that has been purified and spray dried but notthermally activated) and the thermally activated Acti-Gel 208 of Example5;

FIG. 3 is a graph showing the pore size distribution of Min-U-Gel 400®(natural attapulgite that has been air classified but has not beenthermally activated) and the thermally activated Min-U-Gel 400 ofExample 13;

FIG. 4 is a Scanning Electron Microscope (SEM) image of Example 5 at lowmagnification (×200);

FIG. 5 is a SEM image of Example 13 at low magnification (×2500);

FIG. 6 is a SEM image of Example 5 at high magnification (×25000);

FIG. 7 is a SEM image of Example 13 at high magnification (×25000); and

FIG. 8 is a graph illustrating bleaching efficiency.

DETAILED DESCRIPTION

This disclosure relates to thermally activated clay products for oilbleaching: decolorizing and/or for HVO/renewable diesel feedstock oilpretreatment. The clay products disclosed herein comprise or may beattapulgite. Attapulgite is sometimes referred to as palygorskite. Toavoid confusion, as used herein, the term “attapulgite” meansattapulgite and/or palygorskite. As a preliminary matter, thepermeability discussed herein relates to permeability in oil, notpermeability in water. A material's permeability in oil is known bythose of skill in the art to be different than the material'spermeability in water.

The purpose of oil bleaching is typically to remove the color pigmentsand impurities contained in edible and non-edible oils. As discussedearlier, typically, acid activated bleaching clays (e.g., acid-activatedbentonite) are used to adsorb the color pigments. Although such acidactivated bleaching clays may be beneficial, the bleaching process timeof such clays (and other clays) is relatively long because bleachingclays, including acid activated bleaching clays, have very lowpermeability in oil. Usually, permeability in oil is inversely relatedto the bleaching clay's bleaching efficiency as smaller particle sizestypically result in higher bleaching activity but lower permeability.Slow permeability is undesirable because it substantially lowersprocessing throughput rates. Oil refiners, in choosing a bleaching clayare typically forced to compromise between getting the mostdecolorization per amount of bleaching clay versus processing speed.Moreover, use of acid activated bleaching clays (e.g., calcium bentoniteand the like) comes with other drawbacks as well such as undesirableamounts of soluble metals that may be transferred into the decolorizedoil during processing.

Disclosed herein is a novel bleaching clay product that can be used asan adsorbent for oil bleaching (e.g., decolorizing) edible and/ornon-edible oil. Besides removing color red and chlorophyll, the novelbleaching clay product disclosed herein also removes peroxide,phosphorus, metals and calcium very effectively in HVO/renewable dieselfeedstock oil pretreatment. Such novel bleaching product has highpermeability in oil (relative to other bleaching clays) and highbleaching efficiency, which significantly reduces bleaching processtime. Edible oil may include, but is not limited to, vegetable oiland/or (edible) animal derived oil. Exemplary edible vegetable oil mayinclude, but is not limited to, canola, coconut, corn germ, cottonseed,olive, palm, peanut, rapeseed, safflower, sesame seed, soybean,sunflower or mixtures thereof. Edible animal-derived oil may include,but is not limited to, lard, tallow, fish oil or mixtures thereof.Non-edible oil may include, but is not limited to, non-edible vegetableoil, non-edible animal-derived oil, petroleum derived oil, mineral oil,insulating oil(s), rolling oil(s), waste oil(s), lubricant(s),grease(s), or mixtures thereof. Non-edible vegetable oil may include,but is not limited to, soybean oil, rapeseed oil, sunflower oil, palmoil, jojoba oil, linseed oil, castor oil, feedstock oil for renewablediesel/HVO, or mixtures thereof. The feedstock oil for renewablediesel/HVO (also referred to as renewable diesel feedstock oil, HVOfeedstock oil, renewable diesel/HVO feedstock oil) may comprise, but isnot limited to, vegetable oil(s) (e.g., non-edible vegetable oil oredible vegetable oil or mixtures thereof), used cooking oil(s), animalfat(s), Distiller's Dried Grains with Solubles (DDGS) oil, acid oil(s),distillate(s), distillation pitch(es), sludge oil(s), or mixturesthereof. For example, the feedstock oil for renewable diesel/HVO maycomprise soybean oil. Nonedible animal-derived oil may include, but isnot limited to, low grade tallow, neat's-foot oil(s), or mixturesthereof.

In an embodiment, the bleaching clay product comprises attapulgite thathas been thermally activated by heating. Such bleaching clay product mayhave a permeability in oil in the range of 0.04-3 darcy. In anotherembodiment, the bleaching product may further have a bleachingefficiency for Lovibond red of 50%-99%, 50%-95%, or up to 99%. In afurther refinement, in any one of the embodiments above, the bleachingclay product may have a surface area of 45-140 m²/g, or 100-140 m²/g, or80-140 m²/g. In a further refinement, in any one of theembodiments/refinements above, the bleaching clay product may have aporosity of 70-90%, or 76-85%, or 79-85%, or 70-82%. In a furtherrefinement, in any one of the embodiments/refinements above, thebleaching clay product may have a pore volume of 1-3 mL/g or 1-2 mL/g,or 1.4-2 mL/g, or 1.6-1.8 mL/g. In any one of the embodiments orrefinements above, the attapulgite may be thermally activated by heatingat a temperature in the range of 300-850° C., or 300-900° C., or400-850° C. In any one of the embodiments or refinements above, thebleaching clay product may have intrinsic pores in the range of 17-30 nmand/or inter pores in the range of 2-32 microns.

In an embodiment, the bleaching clay product comprises attapulgite thathas been thermally activated by heating. Such bleaching clay product mayhave a permeability in oil in the range of 0.04-3 darcy. In anotherembodiment, the bleaching product may further have a bleachingefficiency for Lovibond red of 50%-95% or up to 95%. In a furtherrefinement, in any one of the embodiments above, the bleaching productmay have a surface area of 50-140 m²/g or 80-140 m²/g. In a furtherrefinement, in any one of the embodiments/refinements above, thebleaching clay product may have a porosity of 70-85% and/or a porevolume of 1.4-2 mL/g. In a further refinement, in any one of theembodiments/refinements above, the bleaching clay product may have aporosity of 76-85% and/or a pore volume of 1.4-2 mL/g. In any one of theembodiments or refinements above, the attapulgite may be thermallyactivated by heating at a temperature in the range of 300-900° C., or300-850° C., or 600-850° C. In any one of the embodiments or refinementsabove, the bleaching clay product may have intrinsic pores in the rangeof 17-30 nm and/or inter pores in the range of 2-32 microns.

In an embodiment, the bleaching clay product comprises attapulgite thathas been thermally activated by heating. Such bleaching clay product mayhave a permeability in oil in the range of 0.05-2.4 darcy. In anotherembodiment, the bleaching clay product may further have a bleachingefficiency for Lovibond red of 50%-90% or up to 90%. In a furtherrefinement, in any one of the embodiments above, the bleaching clayproduct may have a surface area of 80-135 m²/g. In a further refinement,in any one of the embodiments/refinements above, the bleaching clayproduct may have a porosity of 70-85% and/or a pore volume of 1.4-2mL/g. In a further refinement, in any one of the embodiments/refinementsabove, the bleaching clay product may have a porosity of 76-85% and/or apore volume of 1.4-2 mL/g. In any one of the embodiments or refinementsabove, the attapulgite may be thermally activated by heating at atemperature in the range of 400-850° C. In any one of the embodiments orrefinements above, the bleaching clay product may have intrinsic poresin the range of 17-30 nm and/or inter pores in the range of 2-32microns.

In an embodiment, the bleaching clay product comprises attapulgite thathas been thermally activated by heating. Such bleaching clay product mayhave a permeability in oil in the range of 0.05-2.4 darcy. In anotherembodiment, the bleaching clay product may further have a bleachingefficiency for Lovibond red of 70%-90%, or 76% to 90% or up to 90%. In afurther refinement, in any one of the embodiments above, the bleachingclay product may have a surface area of 115-135 m²/g. In a furtherrefinement, in any one of the embodiments/refinements above, thebleaching clay product may have a porosity of 70-85% and/or a porevolume of 1.4-2.0 mL/g. In a further refinement, in any one of theembodiments/refinements above, the bleaching clay product may have aporosity of 76-85% and/or a pore volume of 1.4-2.0 mL/g. In any one ofthe embodiments or refinements above, the attapulgite may be thermallyactivated by heating at a temperature in the range of 600-900° C. or600-850° C. In any one of the embodiments or refinements above, thebleaching clay product may have intrinsic pores in the range of 17-30 nmand/or inter pores in the range of 2-32 microns.

In any one of the embodiments/refinements above, the attapulgite may befree of acid activation. As used here acid activation means contactingattapulgite with a mineral acid or an organic acid to improve surfacearea, porosity and surface acidity. Typical acid activation may includesoaking the clay in a mineral or organic acid (e.g., sulfuric orhydrochloric acid) and then washing out the acid and leachable salts orimpregnating the clay with the acid, without washing. In any one of theembodiments/refinements above, the attapulgite may be free of residualacid (may be acid-free). In any one of the embodiments/refinementsabove, the bleaching clay product may be free of acid activation. In anyone of the embodiments/refinements above, the bleaching clay product maybe free of residual acid (may be acid-free).

In any one of the embodiments/refinements above the bleaching clayproduct has a bleaching efficiency for Lovibond red at a loading of0.5-10 wt. % bleaching clay product to oil and a contact time of 1-30minutes for bleaching.

In any one of the embodiments/refinements above, the attapulgite may bespray dried or agglomerated with or without a binder prior to thermalactivation or agglomerated during thermal activation.

In each of the embodiments/refinements above, the bleaching clay productmay have: (a) no more than 4 ppm soluble lead as measured by the FCC(Food Chemicals Codex), or 0-4 ppm soluble lead as measured by the FCC,or less than 4 ppm soluble lead as measured by the FCC, or no more than0.6 ppm soluble lead as measured by the FCC, or between 0-0.6 ppmsoluble lead as measured by the FCC; and/or (b) no more than 1 ppmsoluble arsenic as measured by the FCC, or 0-0.8 ppm soluble arsenic asmeasured by the FCC, or no more than 0.8 ppm soluble arsenic as measuredby the FCC, or 0-0.8 ppm soluble arsenic as measured by the FCC.

In an embodiment, the attapulgite that has been thermally activated mayhave a d₉₀ of 65-95 μm and/or a d₅₀ of 25-35 μm and/or a d₁₀ of 5-15 μm.

In each of the embodiments/refinements above, the attapulgite is or maybe thermally activated at a temperature and associated time duration atwhich collapse of the crystalline structure of the attapulgite does notoccur.

In any one of the embodiments/refinements above, the attapulgite (afterthermal activation): may be unsintered or free of sintered attapulgiteparticles; or may be substantially unsintered or substantially free ofsintered attapulgite particles.

Disclosed herein is a novel product. The product may compriseattapulgite that has been thermally activated. The product may have: (a)a permeability in an oil in the range of 0.04-3 darcy; (b) a surfacearea of 45-140 m²/g or 80-140 m²/g; (c) a removal efficiency in the oilfor phosphorus of 50% to 100%; and (d) a removal efficiency in the oilfor a metal of 50% to 100%. The product and/or the attapulgite may beacid-free or free of residual acid or free of acid activation, and theoil may comprise or is a feedstock oil for hydrotreated vegetable oil(HVO) or renewable diesel.

In an embodiment, the product or the attapulgite may have a permeabilityin the range of 0.04-0.07 darcy or 0.04-0.19 darcy or 1-3 darcy or 1.5-3darcy.

In any one or more of the product, embodiments or refinements above, themetal may be or may include calcium, magnesium, potassium, copper, oriron.

In any one or more of the product, embodiments or refinements above, theproduct may have a removal efficiency in the oil for peroxide of 50% to100% and/or a removal efficiency in the oil for chlorophyll of 50% to100% and/or a bleaching efficiency in the oil for Lovibond red of 65% to100%.

In any one or more of the embodiments or refinements above, the productmay have a removal efficiency in the oil for phosphorus of 50% to 100%that leaves less than 2 ppm phosphorus content in the oil.

In any one or more of the embodiments or refinements above, the productmay have removal efficiency in the oil for the metal of 50% to 100% thatleaves less than 10 ppm total metal content in the oil.

In any one or more of the embodiments or refinements above, the productmay have removal efficiency in the oil for calcium of 50% to 100% thatleaves less than 2 ppm calcium content in the oil.

In any one or more of the embodiments or refinements above, the productmay have removal efficiency in the oil for chlorophyll of 50% to 100%that leaves less than 0.02 ppm chlorophyll content in the oil or lessthan 0.1 ppm of chlorophyll in the oil.

In any one or more of the product, embodiments or refinements above, theattapulgite that has been thermally activated has a porosity of 70-85%and/or a pore volume of 1-2 mL/g.

In an embodiment, the attapulgite that has been thermally activated mayhave a d₉₀ of 65-95 μm and/or a d₅₀ of 25-35 μm and/or a d₁₀ of 5-15 μm.

In any one or more of the product, embodiments or refinements above, theproduct may have intrinsic pores in the range of 17-30 nm and/or interpores in the range of 2-32 microns.

In each of the embodiments/refinements above, the attapulgite is or maybe thermally activated at a temperature and associated time duration atwhich collapse of the crystalline structure of the attapulgite does notoccur.

In any one of the embodiments/refinements above, the attapulgite (afterthermal activation): may be unsintered or free of sintered attapulgiteparticles; or may be substantially unsintered or substantially free ofsintered attapulgite particles.

Disclosed herein is a novel method for treating an oil. The method maycomprise: contacting for a contact time the oil with a productcomprising attapulgite, the contact time in the range 4-35 minutes,wherein the attapulgite has been thermally activated, wherein theproduct is free of residual acid; and separating the product from theoil to recover a treated oil, wherein the treated oil has a lower amountof phosphorus than the oil had prior to the contacting and has a loweramount of a metal than the oil has prior to the contacting, whereinfurther the treated oil has (a) less than 2 parts per million (ppm) ofphosphorus or less than 0.5 ppm of phosphorus and (b) less than 10 ppmof total metal content or less than 0.5 ppm of the metal; wherein thebleaching clay product has a permeability in oil in the range of 0.04-3darcy, wherein the oil comprises a feedstock oil for hydrotreatedvegetable oil (HVO) or renewable diesel.

In an embodiment, the metal may include or may be calcium, magnesium,potassium, copper, iron or mixtures thereof. In a refinement, the metalincludes or is calcium. In a further refinement, the treated oil mayhave less than 2 parts per million (ppm) of calcium content or less than0.5 ppm calcium content.

In any one or more of the method, embodiments or refinements above, thetreated oil may have a lower amount of peroxide than the oil had priorto the contacting. In a refinement, the treated oil may have 1-3 meq/kgperoxide value.

In any one or more of the method, embodiments or refinements above, thetreated oil may have a lower amount of chlorophyll than the oil hadprior to the contacting. In a refinement, the treated oil may have 0 to0.1 parts per million (ppm) of chlorophyll or may have 0 to less than0.02 ppm of chlorophyll.

In any one or more of the method, embodiments or refinements above, thetreated oil may have a lower red color than the oil had prior to thecontacting. In a refinement, the red color is a Lovibond red and theproduct may have a bleaching efficiency of 50% to 99% for Lovibond red.

In any one or more of the method, embodiments or refinements above, theproduct may have a permeability in oil in the range of 0.04-0.19 darcyor 1.5-3 darcy or 2-3 darcy.

In any one or more of the method, embodiments or refinements above, thecontacting may be at a temperature of 80-125° C.

In any one or more of the product, embodiments or refinements above, theattapulgite that has been thermally activated has a porosity of 70-85%and/or a pore volume of 1-2 mL/g.

In any one of the embodiments or refinements above, the bleaching clayproduct may have intrinsic pores in the range of 17-30 nm and/or interpores in the range of 2-32 microns.

In each of the embodiments/refinements above, the attapulgite is or maybe thermally activated at a temperature and associated time duration atwhich collapse of the crystalline structure of the attapulgite does notoccur.

In any one of the embodiments/refinements above, the attapulgite (afterthermal activation): may be unsintered or free of sintered attapulgiteparticles; or may be substantially unsintered or substantially free ofsintered attapulgite particles.

Preparation of the Product

The method of producing the products discussed above may comprisethermally activating a material that includes (or is) attapulgite toproduce a product that has a permeability in oil in the range of 0.04 to3 darcy.

In one embodiment of the method, the thermally activating may includeheating the material in a muffle furnace, or the like, at a temperaturein the range of 300 to 850° C. or 300 to 900° C. for a duration of 15 to50 minutes. In a refinement of the method or embodiment thereof, theproduct produced by such thermal activation may further have: (a) ableaching efficiency for Lovibond red of 50%-99%, or 50%-95%, or up to99%; and/or (b) a removal efficiency for phosphorus of 50%-100%,70%-100%, or 70%-99%, or up to 100%; and/or (c) a removal efficiency forcalcium of 50%-100%, 70%-100%, or 70%-99%, or up to 100%; and/or (d) aremoval efficiency for chlorophyll of 50%-100%, 50%-99%, or 70%-100%, orup to 100%; and/or (e) a removal efficiency for peroxide of 40%-80%,50%-70%, or 55%-70%, or up to 70%. In a further refinement of themethod, embodiment or any one of the refinements thereof, the productmay have a surface area of 45-140 m²/g or 100-140 m²/g or 80-140 m²/g.In a further refinement of the method, embodiment or any one of therefinements thereof, the product may have a porosity of 70-90%, or76-85% or 70-82%. In a further refinement, in any one of theembodiments/refinements above, the product may have a pore volume of 1-3mL/g, or 1-2 mL/g, or 1.4-2 mL/g, or 1.6-1.8 mL/g. In any one of theembodiments or refinements above, the product may have intrinsic poresin the range of 17-30 nm and/or inter pores in the range of 2-32microns.

In another embodiment of the method, the material may be thermallyactivated to produce a product that has a permeability in oil in therange of 0.04 to 3 darcy by heating the material in a muffle furnace, orthe like, at a temperature in the range of 300-750° C. or 300-800° C.for a duration of 20 to 45 minutes. In a refinement of the method orembodiment thereof, the product produced by such thermal activation bymay further have: (a) a bleaching efficiency for Lovibond red of 50%-95%or up to 95%; and/or (b) a removal efficiency for phosphorus of50%-100%, 70%-100%, or 70%-99%, or up to 100%; and/or (c) a removalefficiency for calcium of 50%-100%, 70%-100%, or 70%-99%, or up to 100%;and/or (d) a removal efficiency for chlorophyll of 50%-100%, 50%-99%, or70%-100%, or up to 100%; and/or (e) a removal efficiency for peroxide of40%-80%, 50-70%, or 55-70%, or up to 70%. In a further refinement of themethod, embodiment or any one of the refinements thereof, the bleachingproduct may have a surface area of 50-140 m²/g or 80-140 m²/g. In afurther refinement of the method, embodiment or any one of therefinements thereof, the bleaching clay product may have a porosity of70-85% or 76-85%. In a further refinement of the method, embodiment orany one of the refinements thereof, the bleaching clay product may havea pore volume of 1.4-2 mL/g. In any one of the embodiments orrefinements above, the bleaching clay product may have intrinsic poresin the range of 17-30 nm and/or inter pores in the range of 2-32microns.

In another embodiment of the method, the material may be thermallyactivated to produce a product that has a permeability in oil in therange of 0.5 to 2.4 darcy by heating the material in a muffle furnace,or the like, at a temperature in the range of 400-850° C. for a durationof 20 to 40 minutes. In a refinement of the method or embodimentthereof, the product produced may further have: (a) a bleachingefficiency for Lovibond red of 50%-90% or up to 90%; and/or (b) aremoval efficiency for phosphorus of 50%-100%, 70%-100%, or 70%-99%, orup to 100%; and/or (c) a removal efficiency for calcium of 50%-100%,70%-100%, or 70%-99%, or up to 100%; and/or (d) a removal efficiency forchlorophyll of 50%-100%, 50-99%, or 70%-100%, or up to 100%; and/or (e)a removal efficiency for peroxide of 40%-80%, 50%-70%, or 55%-70%, or upto 70%. In a further refinement of the method, embodiment or any one ofthe refinements thereof, the product may have a surface area of 80-135m²/g. In a further refinement, of the method, embodiment or any one ofthe refinements thereof, the bleaching clay product may have a porosityof 76-85% or 79-82%. In a further refinement of the method, embodimentor any one of the refinements thereof, the bleaching clay product mayhave a pore volume of 1.4-2 mL/g. In any one of the embodiments orrefinements above, the product may have intrinsic pores in the range of17-30 nm and/or inter pores in the range of 2-32 microns.

In another embodiment of the method, the material may be thermallyactivated to produce a product that has a permeability in oil in therange of 0.05 to 2.4 darcy by heating the material in a muffle furnace,or the like, at a temperature in the range of 600-850° C. for a durationof 20 to 35 minutes. In a refinement of the method or embodimentthereof, the product produced may further have: (a) a bleachingefficiency for Lovibond red of 70%-90%, or 76% to 90% or up to 90%;and/or (b) a removal efficiency for phosphorus of 50%-100%, 70%-100%, or70%-99%, or up to 100%; and/or (c) a removal efficiency for calcium of50%-100%, 70%-100%, or 70%-99%, or up to 100%; and/or (d) a removalefficiency for chlorophyll of 50%-100%, 50%-99%, or 70%-100%, or up to100%; and/or (e) a removal efficiency for peroxide of 40%-80%, 50%-70%,or 55%-70%, or up to 70%. In a further refinement of the method,embodiment or any one of the refinements thereof, the product may have asurface area of 115-135 m²/g. In a further refinement of the method,embodiment or any one of the refinements thereof, the product may have aporosity of 76-85% or 79-82%. In a further refinement of the method,embodiment or any one of the refinements thereof, the product may have apore volume of 1.4-2 mL/g. In any one of the embodiments or refinementsabove, the product may have intrinsic pores in the range of 17-30 nmand/or inter pores in the range of 2-32 microns.

In another embodiment of the method, the material may be thermallyactivated to produce a product that has a permeability in oil in therange of 2 to 2.4 darcy by heating the material at a temperature in therange of 695-750° C. for a duration of 28 to 32 minutes. In a refinementof the method or embodiment thereof, the product produced may furtherhave: (a) a bleaching efficiency for Lovibond red of 70%-82%, or 76% to82% or up to 82%; and/or (b) a removal efficiency for phosphorus of50%-100%, 70%-100%, or 70%-99%, or up to 100%; and/or (c) a removalefficiency for calcium of 50%-100%, 70%-100%, or 70%-99%, or up to 100%;and/or (d) a removal efficiency for chlorophyll of 50%-100%, 50%-99%, or70%-100%, or up to 100%; and/or (e) a removal efficiency for peroxide of40%-80%, 50%-70%, or 55%-70%, or up to 70%. In a further refinement ofthe method, embodiment or any one of the refinements thereof, theproduct may have a surface area of 118-127 m²/g. In a further refinementof the method, embodiment or any one of the refinements thereof, theproduct may have a porosity of 78-82%. In a further refinement of themethod, embodiment or any one of the refinements thereof, the productmay have a pore volume of 1.4-2 mL/g. In any one of the embodiments orrefinements above, the product may have intrinsic pores in the range of17-30 nm and/or inter pores in the range of 2-32 microns.

In another embodiment of the method, the material may be thermallyactivated to produce a product that has a permeability in oil in therange of 0.04 to 0.19 darcy or 0.04 to 0.07 darcy by heating thematerial at a temperature in the range of 400-850° C. for a duration of28 to 32 minutes. In a refinement of the method or embodiment thereof,the product produced may further have: (a) a bleaching efficiency forLovibond red of 70%-99%, or 70%-95% or up to 99%; and/or (b) a removalefficiency for phosphorus of 50%-100%, 70%-100%, or 70%-99%, or up to100%; and/or (c) a removal efficiency for calcium of 50%-100%, 70%-100%,or 70%-99%, or up to 100%; and/or (d) a removal efficiency forchlorophyll of 50%-100%, 50%-99%, or 70%-100%, or up to 100%; and/or (e)a removal efficiency for peroxide of 40%-80%, 50%-70%, or 55%-70%, or upto 70%. In a further refinement of the method, embodiment or any one ofthe refinements thereof, the product may have a surface area of 80-135m²/g. In a further refinement of the method, embodiment or any one ofthe refinements thereof, the product may have a porosity of 70-82%. In afurther refinement of the method, embodiment or any one of therefinements thereof, the product may have a pore volume of 1-2 mL/g. Inany one of the embodiments or refinements above, the product may haveintrinsic pores in the range of 17-30 nm and/or inter pores in the rangeof 2-32 microns.

In the method or any one of the embodiments/refinements above, theattapulgite is, or may be, thermally activated at a selected temperaturefor a duration at which collapse of the crystalline structure of theattapulgite does not occur.

In the method or any one of the embodiments/refinements above theattapulgite may have been spray dried or agglomerated (with or without abinder) prior to thermal activation or agglomerated during thermalactivation. Spray drying techniques are known to those of ordinary skillin the art in the clay industry. One exemplary known method is toprepare a slurry of attapulgite and water, and utilize a spray dryer todisperse the slurry into droplets using high pressure nozzles, disks orthe like. The temperature of the inlet and outlet air of the spray dryerdepends on the dryer used. The droplets then become generally roundedagglomerations of attapulgite particles and are collected downstream ofthe drying chamber. Alternatively, other appropriate methods known inthe art to spray dry clay or agglomerate clay (e.g, flash drying/heattreating, fluid bed drying, use of a high-shear mixer such as a pinmixer, paddle mixer, ribbon blender, rotary drum, etc.) may be usedprior to thermal activation.

In the method or any one of the embodiments/refinements above theattapulgite may be free of acid activation. In the method or any one ofthe embodiments/refinements above the attapulgite may be free ofresidual acid (the attapulgite may be acid-free). In the method or anyone of the embodiments/refinements above, the product may be free ofacid activation. In the method or any one of the embodiments/refinementsabove, the product may be free of residual acid (the bleaching clayproduct may be acid-free).

Attapulgite/palygorskite is a magnesium aluminium phyllosilicate withthe chemical formula (Mg,Al)₂Si₄O₁₀(OH).₄H₂O. The percentages of thevarious impurity elements such as iron, calcium, sodium and potassium,as well as some relatively smaller amounts of lead and/or arsenic mayvary depending on the deposit from which the attapulgite is sourced. Thebulk chemistry of the attapulgite used as feed material impacts theextractable metal properties of the resulting bleaching clay product assuch impurities can form extractable metals when the bleaching clayproduct comes into contact with oil. Thus, in the method or any one ofthe embodiments/refinements above, the attapulgite may have undergone apurification process to reduce impurities prior to the thermalactivation disclosed herein, which may further reduce impurities in thebleaching clay product. Purification processes are known in the art. Asused herein, purification process(es) that the attapulgite may haveundergone to reduce impurities does(do) not include acid activation oracid washing.

In the method or any one of the embodiments/refinements above theproduct produced may have: (a) no more than 4 ppm soluble lead asmeasured by the FCC, or 0-4 ppm soluble lead as measured by the FCC, orless than 4 ppm soluble lead as measured by the FCC, or no more than 0.6ppm soluble lead as measured by the FCC, or between 0-0.6 ppm solublelead as measured by the FCC; and/or (b) no more than 1 ppm solublearsenic as measured by the FCC, or 0-0.8 ppm soluble arsenic as measuredby the FCC, or no more than 0.8 ppm soluble arsenic as measured by theFCC, or 0-0.8 ppm soluble arsenic as measured by the FCC.

Bleaching/Treating Process for Oil

In an application, the oil to be decolorized/bleached and any one of thedisclosed products described above is combined in a suitable vessel toproduce a slurry. A standard test method such as The American OilChemists' Society (AOCS) Cc8d-55 test method (this method determines thecolor of the test sample after treatment with alkali and a specifiedbleaching earth) can be used for bleaching process. The loading may bethat amount of the bleaching clay product sufficient to reduce theamount of red color pigment in the oil in a given the contact time suchthat a bleaching efficiency of at least 50% is achieved. In anembodiment, the loading may be in the range of 0.5-10 wt. %, or 2-4 wt.%, or about 3 wt. %. The contact time may be in the range of about 1 toabout 30 minutes. In one embodiment, the contact time may be in therange of 4-10 minutes. In another embodiment, the contact time may be inthe range of 4-6 minutes. In another embodiment, the contact time may beabout 5 minutes.

The resulting slurry may be heated to and maintained at 80-130° C. orabout 115-125° C. for a time period sufficient to reduce the amount ofred color pigment in the oil using the disclosed bleaching clay product.

The bleached oil is then recovered from the slurry by any appropriatemethod known to those of skill in the art. For example, the bleached oilmay be recovered by filtration.

In another application, the oil to be bleached and any one of thedisclosed products described above is combined in a suitable vessel toproduce a slurry. A standard test method such as The American OilChemists' Society (AOCS) Cc8d-55 test method can be used for thebleaching process, AOCS Official Method Cc 13b-45 for measuring colorred, AOCS Official Method Cc 13d-55 for measuring chlorophyll, AOCSSurplus Method Cd 8-53 for measuring peroxide, AOCS Official Method Ca17a-18 for measuring calcium, and AOCS Official Method Ca 17a-18 formeasuring phosphorus. The loading may be that amount of the productsufficient to: (a) reduce the amount of phosphorus in the oil in thegiven contact time such that a removal efficiency of at least 50% isachieved for phosphorus and/or (b) reduce the amount of metal (e.g.,calcium) in the oil in the given contact time such that a removalefficiency of at least 50% is achieved for the metal and/or (c) reducethe amount of chlorophyll in the oil in the given contact time such thata removal efficiency of at least 50% is achieved for chlorophyll and/or(d) reduce the amount of peroxide in the oil in the given contact timesuch that a removal efficiency of at least 50% is achieved for peroxide.The loading may be that amount of the product sufficient to result inthe oil after bleaching/treating (treated oil) having a total metalcontent of 0 to less than 10 ppm, and/or a calcium content of 0 to lessthan 2 ppm, and/or a phosphorus content of 0 to less than 2 ppm and/orchlorophyll content of 0 to 0.5 ppm and/or peroxide content of 1 to lessthan 5 meq/kg. In an embodiment, the loading may be in the range of0.5-10 wt. % or 0.5-4 wt. %, or 1-3 wt. %, or 1-1.5 wt. %. The contacttime may be in the range of about 1 to about 35 minutes. In oneembodiment, the contact time may be in the range of 4-35 minutes. In oneembodiment, the contact time may be in the range of 4-10 minutes. Inanother embodiment, the contact time may be in the range of 4-6 minutes.In another embodiment, the contact time may be about 5 minutes. Inanother embodiment, the contact time may be about 30 minutes. Metal mayinclude Calcium (Ca), magnesium (Mg), potassium (K), copper (Cu), iron(Fe), or mixtures thereof.

The resulting slurry may be heated to and maintained at 80-130° C. or80-125° C. or about 120° C. or about 95° C. for a time period sufficientto: (a) reduce the amount of phosphorus in the oil in the given contacttime such that a removal efficiency of at least 50% is achieved forphosphorus and/or (b) reduce the amount of metal (e.g., calcium) in theoil in the given contact time such that a removal efficiency of at least50% is achieved for the metal and/or (c) reduce the amount ofchlorophyll in the oil in the given contact time such that a removalefficiency of at least 50% is achieved for chlorophyll and/or (d) reducethe amount of peroxide in the oil in the given contact time such that aremoval efficiency of at least 50% is achieved for peroxide. Such timeperiod may be sufficient to result in the oil after bleaching/treating(treated oil) having: a total metal content of 0 to less than 10 ppm,and/or a calcium content of 0 to less than 2 ppm, and/or a phosphoruscontent of 0 to less than 2 ppm and/or chlorophyll content of 0 to 0.5ppm and/or peroxide content of 1 to less than 5 meq/kg.

The bleached/treated oil is then recovered from the slurry by anyappropriate method known to those of skill in the art. For example, thebleached/treated oil may be recovered by filtration.

As discussed earlier herein, oils suitable for bleaching/treatinginclude edible oils and/or non-edible oils. Edible oil may include, butis not limited to, vegetable oil and/or (edible) animal derived oil.Edible vegetable oil may include, but is not limited to, canola,coconut, corn germ, cottonseed, olive, palm, peanut, rapeseed,safflower, sesame seed, soybean, sunflower or mixtures thereof. Edibleanimal-derived oil may include, but is not limited to, lard, tallow,fish oil or mixtures thereof. Non-edible oil may include, but is notlimited to, non-edible vegetable oil, non-edible animal-derived oil,petroleum derived oil, mineral oil, insulating oil(s), rolling oil(s),waste oil(s), lubricant(s), grease(s), or mixtures thereof. Non-ediblevegetable oil may include, but is not limited to, soybean oil, rapeseedoil, sunflower oil, palm oil, jojoba oil, linseed oil, castor oil,renewable diesel/HVO feedstock oil, or mixtures thereof. Renewablediesel/HVO feedstock oil may comprise, but is not limited to, vegetableoil(s) (e.g., non-edible vegetable oil or edible vegetable oil ormixtures thereof), used cooking oil(s), animal fat(s), DDGS (Distiller'sDried Grains with Solubles) oil, acid oil(s), distillate(s),distillation pitch(es), sludge oil(s), or mixtures thereof. For example,the feedstock oil for renewable diesel/HVO may comprise soybean oil.Nonedible animal-derived oil may include, but is not limited to, lowgrade tallow, neat's-foot oil(s), or mixtures thereof

Description of Test Methods Permeability

Permeability of thermal activated attapulgite in oil was measuredaccording to Darcy's law using Canola oil under the constant flowcondition.

$Q = \frac{KADP}{\mu L}$

Where Q=Flowrate (cc/sec)=

-   -   μ=Oil viscosity (cP)    -   A=Cross-sectional area open for flow (cm²)    -   DP=Pressure drop within the system (atm)    -   L=length of packed bed (cm)    -   K=Absolute permeability (Darcy)

X-ray Diffraction (XRD)

Bulk powder XRD was analyzed utilizing a PANalytical X'Pert Prodiffractometer using Cu Kα radiation from 4-75° 2Θ with a step size of0.008° 2Θ for 240 seconds/step. The resulting diffraction patterns werethen analyzed using X'Pert HighScore Plus search-match softwareutilizing the ICDD PDF4+ database to identify the phases present.

Surface Area, Pore volume, Pore Size Distribution, Porosity

Surface area was measured by BET (Brunauer-Emmett-Teller) method. Porevolume and pore size distribution of a sample of material was determinedby mercury porosimetry. The mercury porosimetry uses mercury as anintrusion fluid to measure pore volume and surface area of a (weighed)sample of material enclosed inside a sample chamber of a penetrometer.The sample chamber is evacuated to remove air from the pores of thesample. The sample chamber and penetrometer are filled with mercury.Since mercury does not wet the material surface, it must be forced intothe pores by means of external pressure. Progressively higher pressureis applied to allow mercury to enter the pores. The requiredequilibrated pressure is inversely proportional to the size of thepores, only slight pressure is required to intrude the mercury intomacropores, whereas much greater external pressure is required to forcemercury into small pores. The penetrometer reads the volume of mercuryintruded and the intrusion data is used to calculate pore sizedistribution, porosity, average pore size, surface area of the sampleand total pore volume. A Micromeritics AutoPore IV 9500 was used toanalyze the samples herein.

Assuming pores of cylindrical shape, a surface distribution may bederived from the pore volume distribution. An estimate of the totalsurface area of the sample of material can be made from thepressure/volume curve (Rootare, 1967) without using a pore model as

$A = {\frac{1}{\gamma\cos\theta}{\int\limits_{V_{{Hg},0}}^{V_{{Hg},\max}}{pdV}}}$

Where, A=total surface area

-   -   γ=surface tension of the mercury    -   θ=angle of contact of mercury with the material pore wall    -   p=external applied pressure    -   V=pore volume        From the function V=V(p) the integral may be calculated by means        of a numerical method.

From the pressure versus the mercury intrusion data, the instrumentgenerates volume and size distribution of pores following the Washburnequation (Washburn, 1921) as:

$d_{i} = \frac{4\gamma\cos\theta}{P_{i}}$

Where, d_(i)=diameter of pore at an equilibrated external pressure

-   -   γ=surface tension of the mercury    -   θ=angle of contact of mercury with the material pore wall    -   P_(i)=external applied pressure

The average pore diameter is determined from cumulative intrusion volumeand total surface area of the sample of material as:

$D = \frac{4V}{S}$

-   -   Where, D=average pore diameter    -   V=total intrusion volume of mercury    -   S=total surface area

Porosity is the fraction of the total material volume that is taken upby the pore space. Porosity was calculated from mercury intrusion data.

Food Chemical Codex (FCC) Test Method for Soluble Arsenic

Soluble arsenic was measured for natural attapulgite and for thermallyactivated attapulgite using the Food Chemical Codex (FCC) Test Methodfor Clay (Bentonite/Smectite, FCC 5^(th) Edition Monograph). The amountof soluble arsenic was determined as directed under the Arsenic LimitTest (Appendix IIIB of the FCC 5^(th) Edition) using 5.0 mL of theStandard Arsenic Solution and a 25-mL aliquot of the following SampleSolution. Such Sample Solution is prepared by: transferring 8.0 g of thedried sample into a 250-mL beaker containing 100 mL of 1:25 hydrochloricacid, mixing, covering with a watch glass, and boiling gently, stirringoccasionally, for 15 minutes without allowing excessive foaming;filtering the hot supernatant liquid through a rapid-flow filter paperinto a 200-mL volumetric flask, and washing the filter with four 25-mLportions of hot, 1:25 hydrochloric acid, collecting the washings in thevolumetric flask; and cooling the combined filtrates to roomtemperature, adding 1:25 hydrochloric acid to volume, and mixing.

Food Chemical Codex (FCC) Test Method for Soluble Lead

Soluble lead was measured for natural attapulgite and for thermallyactivated attapulgite using the Food Chemical Codex (FCC) Test Methodfor Clay (Bentonite/Smectite, FCC 5^(th) Edition Monograph). A StandardPreparation was prepared by, on the day of use, diluting 3.0 mL of LeadNitrate Stock Solution (Flame Atomic Absorption Method under Lead LimitTest, Appendix IIIB) to 100 mL with water. Each milliliter of the StandPreparation contains the equivalent of 3 μg of lead.

The Test Preparation was prepared by: transferring 3.75 g of driedsample into a 250-mL beaker containing 100 mL of 1:25 hydrochloric acid,stirring, covering with a watch glass, and boiling for 15 minutes;cooling to room temperature, and allowing the insoluble matter tosettle; and decanting the supernatant liquid through a rapid-flow filterpaper into a 400-mL beaker; washing the filter with four 25-mL portionsof hot water, collecting the filtrate in the 400-mL beaker; andconcentrating the combined extracts by gentle boiling to approximately20 mL. (If a precipitate forms, the method instructs for the TestPreparation to add 2 to 3 drops of nitric acid, heat to boiling, andcool to room temperature.) The concentrated extracts were filteredthrough a rapid-flow filter paper into a 50-mL volumetric flask. Theremaining contents of the 400-mL beaker were transferred through thefilter paper and into the flask with water; and diluted to volume withwater, and mixed. The Test Procedure instructs to determine theabsorbances of the Test Preparation and the Standard Preparation at 284nm in a suitable atomic absorption spectrophotometer equipped with alead hollow-cathode lamp, deuterium arc background correction, and asingle-slot burner, using an oxidizing air-acetylene flame. Theabsorbance of the Test Preparation is not greater than that of theStandard Preparation.

Test Method for Measuring Color Red

Color red was measured herein using AOCS (American Oil Chemists'Society) Official Method Cc 13b-45. This method determines color bycomparison with glasses of known color characteristics.

Test Method for Measuring Chlorophyll

Chlorophyll was measured herein using AOCS (American Oil Chemists'Society) Official Method Cc 13d-55. This method is used to determinemg/kg (ppm) of chlorophyll-related pigments (predominantly pheophytin a)in oils from spectrophotometric absorption measurements at 630, 670, and710 nm.

Test Method for Measuring Peroxide

Peroxide was measured herein using AOCS (American Oil Chemists' Society)Surplus Method Cd 8-53. This method determines all substances, in termsof milliequivalents of peroxide per 1000 grams of sample, that oxidizepotassium iodide (KI) under the conditions of the test. The substancesare generally assumed to be peroxides or other similar products of fatoxidation.

Test Method for Measuring Calcium

Calcium was measured herein using AOCS (American Oil Chemists' Society)Official Method Ca 17a-18. Solvent-diluted vegetable oils are analyzedfor trace elements directly by Inductively Coupled Plasma OpticalEmission Spectroscopy (ICP-OES).

Test Method for Measuring Phosphorus

Phosphorus was measured herein using AOCS (American Oil Chemists'Society) Official Method Ca 17a-18. Solvent-diluted vegetable oils areanalyzed for trace elements directly by Inductively Coupled PlasmaOptical Emission Spectroscopy (ICP-OES).

Examples 1-17

The bleaching clay products of Examples 1-17 each comprised thermallyactivated attapulgite. For clarity, the bleaching clay productsdisclosed herein may be used for decoloring and/or removal of impurities(e.g., phosphorus, metal, calcium, peroxide). As such, the novelproducts disclosed herein may be referred to as bleaching products,bleaching clay products or products, each of which may be used inapplications to decolor and/or remove impurities. The bleaching clayproducts of Examples 1-8 were prepared using the commercially availableActi-Gel 208® (Active Minerals International, LLC) as feed material, andExamples 9-16 were prepared using the commercially available Min-U-Gel400® (Active Minerals International, LLC) as feed material, and Example17 was prepared using the commercially available Min-U-Gel 200® (ActiveMinerals International, LLC) as feed material. Acti-Gel 208, Min-U-Gel400 and Min-U-Gel 200 are attapulgite products. The Acti-Gel 208 productis natural attapulgite that has been purified and spray dried. TheMin-U-Gel 400 and Min-U-Gel 200 products are non-purified naturalattapulgite that has been air classified. The major elementalcompositions of Acti-Gel 208 and of Min-U-Gel 400 and of Min-U-Gel 200,as determined by wave-length dispersive x-ray fluorescence (XRF)analysis, is shown in Table 1.

TABLE 1 Major Oxide Composition of purified natural attapulgite productActi-Gel 208 and air classified natural attapulgite Min-U-Gel 400,Min-U-Gel 200 used as feed materials (Ignited Basis). Total Chemistry asdetermined by XRF (expressed Acti-Gel Min-U-Gel Min-U-Gel as oxides)¹208 ® 400 ® 200 ® SiO₂ (wt. %) 51.1 66.2 66.2 Al₂O₃ (wt. %) 10.8 12.111.7 Fe₂O₃ (wt. %) 3.5 4.2 4.0 CaO (wt. %) 2.2 2.8 2.9 MgO (wt. %) 8.49.9 9.7 Na₂O (wt. %) 0.5 K₂O (wt. %) 0.6 1.1 1.1 TiO₂ (wt. %) 0.4 0.60.6 P₂O₅ (wt. %) 0.6 1.0 1.0 Free Moisture, 9.0 13.5 12.5 wt. % @ 220°F. (104° C.) Residue (wet) % 0.01 0.005 6.9 retained on 325 mesh screen¹Although the elements are reported as oxides, they are actually presentas comp ex aluminosilicates.

For each of examples 1-17, 100 g of the feed material was placed in aceramic boat and heated in a muffle furnace for 30 minutes to thermallyactivate the attapulgite. During thermal activation, agglomeration ofthe attapulgite occurred. The temperature for thermal activation of eachexample is listed in Table 2. Table 2 also lists the surface area of thefeed materials (Acti-Gel 208, Min-U-Gel) and the surface area of thebleaching clay products of Examples 1-17 (attapulgite post thermalactivation), as the surface area does not appreciably change withthermal activation up to a certain temperature. Examples 1-8 wereprepared using Acti-Gel 208 as the feed material, and Examples 9-16 wereprepared using Min-U-Gel 400 as the feed material. Example 17 wasprepared using Min-U-Gel 200 as the feed material. The surface area foreach entry in Table 2 was measured by BET method.

TABLE 2 Thermal activation conditions for attapulgite feed materials andresulting surface area. Thermal Activation Surface Examples Temperature(° C.) Area (m²/g) Acti-Gel ® 208¹ 142 Example 1 300 140 Example 2 400130 Example 3 500 121 Example 4 600 125 Example 5 700 120 Example 6 80053 Example 7 900 8 Example 8 1000 Min-U-Gel ® 400² 142 Example 9 300 140Example 10 400 130 Example 11 500 126 Example 12 600 123 Examples 13 700117 Example 14 800 83 Example 15 900 6 Example 16 1000 Min-U-Gel ® 200³98 Example 17 700 88 ¹Active Minerals International, LLC ²ActiveMinerals International, LLC ³Active Minerals International, LLC

FIG. 1 illustrates a comparison between the XRD patterns of thethermally activated attapulgite of Example 5 and the feed material(Acti-Gel 208) prior to thermal activation. FIG. 1 shows that the strongpalygorskite diffraction peaks in natural attapulgite (Acti-Gel 208)become very weak after heat treatment at 700° C. This indicates thatpalygorskite crystal structure rearranges and becomes disordered due tothe loss of structural water at high temperature. Amorphization of thepalygorskite crystal structure also reduces surface area. When thetemperature is over 900° C., palygorskite crystal structure completelycollapses and results in very low surface area.

FIG. 2 shows the pore size distribution of a spray dried and purifiednatural attapulgite (Acti-Gel 208) before thermal activation and afterit has been thermally activated (Example 5) as measured by mercuryintrusion. Similarly, FIG. 3 shows the pore size distribution of (an airclassified) natural attapulgite (Min-U-Gel 400) before thermalactivation and after it has been thermally activated (Example 13) asmeasured by mercury intrusion. As used herein, an “intrinsic pore” is apore that is (a) disposed in the surface of a particle of attapulgite or(b) disposed in the structure of a particle of attapulgite. As usedherein an “inter pore” is a pore that is (a) disposed between particlesof attapulgite or (b) disposed between agglomerated particles ofattapulgite.

In FIG. 2 , the bimodal distribution shows small intrinsic pores around25 nanometers (nm), and large inter pores around 30 microns for thespray dried and purified natural attapulgite of Acti-Gel 208.

In FIG. 3 , the bimodal distribution shows small intrinsic pores around15 nm, and large inter pores around 2 microns for the air classifiednatural attapulgite of Min-U-Gel 400.

As determined for Examples 5 and 13, pore volume was greater than 1.4mL/g, porosity was greater than 73%. For the thermally activated, spraydried and purified attapulgite of Example 5, the bimodal distribution ofFIG. 2 shows the small intrinsic pores around 30 nm, and large interpores of about 32 microns. For the thermally activated, air classifiedattapulgite of Example 13, the bimodal distribution of FIG. 3 shows thesmall intrinsic pores around 17 nm and the large inter pores of about 2microns. For the thermally activated attapulgite, (e.g., Example 5 andExample 13) the inventors have found that the smaller intrinsic(nano)pores (17-30 nm) are effective to adsorb pigments in the oil sincethey are closer to the diameter of the pigments. For the thermallyactivated attapulgite, (e.g., Example 5 and Example 13) the inventorshave found that the large inter pores (2-32 microns) facilitate oil toflow through attapulgite particles and increase attapulgite permeabilityin oil.

Table 3 illustrates the pore volume and porosity of the naturalattapulgite of Acti-Gel 208 (purified and spray dried) and of Min-U-Gel400 (non-purified and air classified) as compared to thermally activatedattapulgite (Example 5 and Example 13). Table 3 indicates that theattapulgite structure becomes more porous after high temperature thermalactivation with increasing pore volume and porosity.

TABLE 3 Pore volume and porosity of natural attapulgite (Acti-Gel 208and Min-U-Gel 400) and thermally activated attapulgite (Examples 5, 13and 17). Total intrusion pore volume Porosity d₁₀ d₅₀ d₉₀ Sample (mL/g)(%) (μm) (μm) (μm) Acti-Gel ® 208 1.4931 75.8 Example 5 1.7737 80.5Min-U-Gel ® 400 1.4806 73.6 Example 13 1.8305 78.2 Min-U-Gel ® 200 6.4318.2 63.7 Example 17 1.1853 72.0 9.22 30.6 93.3

FIG. 4 and FIG. 5 are Scanning Electron Microscope (SEM) images ofExample 5 and Example 13 at low magnification (×200, ×2500respectively). The SEM images of FIG. 4 and FIG. 5 show that thethermally activated attapulgite particles are in a generally roundedgranular form in the spray dried purified attapulgite and irregularshapes in the non-purified air classified attapulgite. FIG. 6 and FIG. 7are SEM images of Example 5 and Example 13 at high magnification(×25000). These high magnification SEM images indicate that attapulgiterods remain intact after high temperature treatment at 700° C. eventhough the palygorskite crystal structure becomes amorphous.

Example 18

Permeability of thermally activated attapulgite in oil was measuredaccording to Darcy's law using Canola oil under the constant flowcondition. A commercially available activated bleaching clay (F-105, EPMinerals, LLC) was also measured for comparison.

Table 4 shows the permeability in oil of the commercially availableactivated bleaching clay (F-105), the commercially available Acti-Gel208, the commercially available Min-U-Gel 400, and Examples 1-6 andExamples 9-14 and 17. Table 4 illustrates that the permeability of thethermally activated attapulgite of Examples 1-6 is significantly higherthan the commercially available activated bleaching clay. The comparisonof Example 5 to Example 13 shows that thermal activation of attapulgitethat has undergone agglomeration (e.g., spray drying) prior to thermalactivation (Example 5) increases the permeability of the resultingbleaching clay product as compared to thermal activation of attapulgitethat has not undergone agglomeration (Example 13) prior to thermalactivation. Increasing the thermal activation temperature increasespermeability due to more porous structure as indicated by porosimetryresults.

TABLE 4 Permeability of thermal activated attapulgite (Examples 1-6 and9-14 and 17) in oil. Thermal Activation Permeability in SampleTemperature (° C.) Oil (mDarcy) Activated 9.11 bleaching clay¹Acti-Gel ® 208 700 Example 1 300 903.6 Example 2 400 1525.7 Example 3500 1512.9 Example 4 600 2266.2 Example 5 700 2125.1 Example 6 8002927.8 Min-U-Gel ® 400 34.6 Example 9 300 41.5 Example 10 400 37.7Example 11 500 36.1 Example 12 600 43.3 Example 13 700 53.3 Example 14800 45.6 Example 17 700 190.2 ¹F-105, EP Engineered Clays Corporation ²Active Minerals International, LLC

Example 19

Table 5 shows the Food Chemical Codex (FCC) soluble metals for naturalattapulgite (Acti-Gel 208) that has been purified and naturalattapulgite (Min-U-Gel 400) that has not undergone a purificationprocess, and the thermally activated attapulgite of Examples 5 and 13.Table 5 illustrates that thermally activated attapulgite has low solublearsenic and lead measured by the standard Food Chemical Codex (FCC) testmethods for clay (Bentonite/Smectite, FCC 5th Edition Monograph). Thesesoluble heavy metals are well below FCC limits (5 ppm for arsenic, 40ppm for lead) for food applications.

TABLE 5 Food Chemical Codex (FCC) soluble metals for natural attapulgiteand thermally activated attapulgite. FCC Soluble FCC Soluble SampleArsenic (ppm) Lead (ppm) Acti-Gel ® 208¹ 0.07 3.543 Example 5 0.06 0.568(Acti-Gel 208 thermally activated at 700° C. Min-U-Gel ® 400² 0.0522.963 Example 13 0.792 3.770 (Min-U-Gel ®400 thermally activated at 700°C.) ¹Active Minerals International, LLC ²Active Minerals International,LLC

Example 20

Bleaching efficiency was measured according to The American OilChemists' Society (AOCS) standard test method Cc8d-55. For eachbleaching clay product of Examples 1-17, the oil and the bleaching clayproduct was combined in a suitable vessel to produce a slurry. In eachexample, the oil was an edible oil (soybean oil), and the loading was 3wt. % bleaching clay product to 97 wt. % oil. The slurry was heated to120° C. The contact time for each example was 5 minutes at atmosphericpressure and at a temperature of 120° C. after which the bleaching clayproduct was separated from the oil by filtering.

Table 6 shows that thermal activation increases bleaching efficiency.This is due to increased adsorption capacity in attapulgite by removalof water molecules in the channels of palygorskite crystal structure bythermal treatment. The highest bleaching efficiency is achieved around600-800° C. thermal activation (heating). Further increase of thethermal activation temperature reduces bleaching efficiency as thepalygorskite crystal structure begins to collapse or completelycollapses. “Lovibond red” measures the carotenes present in the oil. Thecolor measurements in Table 6 were read by the Lovibond colorimeter.FIG. 8 further illustrates the bleaching efficiency (%) of the Examplesof Table 6.

${{Bleaching}{efficiency}} = \frac{\begin{matrix}\left( {{{Lovibond}{red}{before}{bleaching}} -} \right. \\\left. {{Lovibond}{red}{after}{bleaching}} \right)\end{matrix} \times 100}{{Lovibond}{red}{before}{bleaching}}$

TABLE 6 Bleaching Efficiency Results for Bleaching Clay Products ThermalActivation Lovibond Lovibond Temperature Red Red Bleaching (° C.) of theBefore After Efficiency Samples Material Bleaching Bleaching (%)Acti-Gel ® 9.1 5.0 45 208¹ Example 2 400 9.1 4.4 52 Example 4 600 9.12.1 77 Example 5 700 9.0 1.9 79 Example 6 800 8.6 1.9 78 Example 7 9008.1 3.8 53 Example 8 1000 10.4 8.3 20 Min-U- 8.3 2.0 76 Gel ® 400Example 10 400 8.3 1.3 84 Example 12 600 8.3 1.2 86 Example 13 700 9.91.0 90 Example 14 800 9.3 1.5 84 Example 15 900 9.3 1.9 80 Example 17700 8.6 1.4 84

Measurements were made on another sample of unbleached soybean oil andrecorded in Table 7. A portion of the sample soybean oil was bleachedwith Example 13 and measurements were recorded in Table 7. Forcomparison, another portion of the sample soybean oil was bleached witha commercial acid activated bleaching clay and measurements wererecorded in Table 7.

As shown in Table 7, bleaching performance of thermally activatedattapulgite in the soybean oil is similar to the commercial acidactivated bleaching earth product (Oil-Dri Supreme™ B81). Besidesremoving color red and chlorophyll, thermally activated attapulgite alsoremoves peroxide, phosphorus, and calcium very effectively in soybeanoil. Based on these results, thermally activated attapulgite can also beused to remove phosphorus and metals in hydrotreated vegetable oil(HVO)/renewable diesel feedstock pretreatment.

TABLE 7 Comparison of thermally activated attapulgite with commercialacid activated bleaching earth product. Chloro- Per- Cal- Phos- phylloxide cium phorus Lovibond Samples (ppm) (meq/kg) (ppm) (ppm) redUnbleached 0.29 5.2 59.84 291.8 10.7 soybean oil Soybean oil −0.02 2.0<0.5 <0.5 3.0 bleached with Example 13 Soybean oil 0.01 2.0 <0.5 <0.54.0 bleached with Commercial acid activated bleaching clay¹ ¹Supreme ™B81, Oil-Dri Corporation of AmericaTable 8 illustrates the exemplary bleaching efficiency and the exemplarychlorophyll, peroxide, calcium, phosphorus removal efficiency in thesample of soybean oil, as calculated below and using the values in Table7.

${{{Removal}{efficiency}} = \frac{\begin{matrix}\left( {{{Chlorophyll}{before}{bleaching}} -} \right. \\\left. {{Chlorophyll}{after}{bleaching}} \right)\end{matrix} \times 100}{{Chlorophyll}{before}{bleaching}}}{{{Removal}{efficiency}} = \frac{\begin{matrix}\left( {{{Peroxide}{before}{bleaching}} -} \right. \\\left. {{Peroxide}{after}{bleaching}} \right)\end{matrix} \times 100}{{Peroxide}{before}{bleaching}}}{{{Removal}{efficiency}} = \frac{\begin{matrix}\left( {{{Calcium}{before}{bleaching}} -} \right. \\\left. {{Calcium}{after}{bleaching}} \right)\end{matrix} \times 100}{{Calcium}{before}{bleaching}}}{{{Removal}{efficiency}} = \frac{\begin{matrix}\left( {{{Phosphorus}{before}{bleaching}} -} \right. \\\left. {{Phosphorus}{after}{bleaching}} \right)\end{matrix} \times 100}{{Phosphorus}{before}{bleaching}}}{{{Bleaching}{efficiency}} = \frac{\begin{matrix}\left( {{{Lovibond}{red}{before}{bleaching}} -} \right. \\\left. {{Lovibond}{red}{after}{bleaching}} \right)\end{matrix} \times 100}{{Lovibond}{red}{before}{bleaching}}}$

TABLE 8 Comparison of thermally activated attapulgite with commercialacid activated bleaching earth product. Chlorophyll Peroxide CalciumPhosphorus Removal Removal Removal Removal Lovibond EfficiencyEfficiency Efficiency Efficiency Red Samples (%) (%) (%) (%) (%)Unbleached soybean oil Soybean oil bleached with 100 62 +99 +99.8 72Example 13 Soybean oil bleached with 97 62 +99 +99.8 63 Commercial acidactivated bleaching clay¹ ¹Supreme ™ B81, Oil-Dri Corporation of America

INDUSTRIAL APPLICABILITY

In general, the foregoing disclosure finds utility in the removal of redcolor pigments and chlorophyll and impurities (peroxide and/orphosphorus and/or metals and/or calcium) contained in edible andnon-edible oils. The foregoing disclosure also finds utility in theremoval of red color pigments and/or chlorophyll and/or peroxide and/orphosphorus and/or metals and/or calcium in hydrotreated vegetable oil(HVO)/renewable diesel feedstock oil pretreatment. Typically, acidactivated bleaching clays have been used to adsorb the color pigments.Although such acid activated bleaching clays may be beneficial, thebleaching process time of such clays is relatively long becausebleaching clays, including acid activated bleaching clays, have very lowpermeability in oil. Usually, permeability in oil is inversely relatedto the bleaching clay's bleaching efficiency as smaller particle sizestypically result in higher bleaching activity but lower permeability.Slow permeability is undesirable because it substantially lowersprocessing throughput rates.

Historically, oil refiners, in choosing a bleaching clay have beentypically forced to compromise between getting the most decolorizationper amount of bleaching clay versus processing speed. Moreover, use ofacid activated bleaching clays (e.g., calcium bentonite and the like)comes with other drawbacks as well such as undesirable amounts ofsoluble metals that may be transferred into the decolorized oil duringprocessing.

The novel bleaching clay products disclosed herein can be used as anadsorbent for oil bleaching (e.g., decolorizing) edible and/ornon-edible oil, and/or for removing phosphorus and/or metals (e.g.,calcium) and/or peroxide in oil or in HVO/renewable diesel feedstockpretreatment. Such bleaching clay products have high permeability in oil(relative to other bleaching clays) and high bleaching efficiency, whichsignificantly reduces bleaching process time. Furthermore, compared tothe acid activated bleaching clays, the bleaching clay productsdisclosed herein do not require the wet processes associated with highproduction cost and other additional costs such as chemicals and wastedisposal The thermal activation undergone by the attapulgite of thebleaching products disclosed herein removes residual organiccontaminants from the attapulgite, thereby making the resultingbleaching products more desirable for use in bleaching edible oils.Furthermore, the novel products disclosed herein are free of residualacid. In other words, the products disclosed herein are acid-free.

From the foregoing, it will be appreciated that while only certainembodiments have been set forth for the purposes of illustration,alternatives and modifications will be apparent from the abovedescription to those skilled in the art. These and other alternativesare considered equivalents and within the spirit and scope of thisdisclosure and the appended claims.

What is claimed is:
 1. A product comprising: attapulgite, wherein theattapulgite has been thermally activated, wherein the product has apermeability in an oil in the range of 0.04-3 darcy, wherein the producthas a surface area of 45-140 m²/g or 80-140 m²/g, wherein the producthas a removal efficiency in the oil for phosphorus of 50% to 100%wherein the product has a removal efficiency in the oil for a metal of50% to 100%, wherein the product is acid-free or free of residual acid,wherein the oil comprises a feedstock oil for hydrotreated vegetable oil(HVO) or renewable diesel.
 2. The product of claim 1, wherein furtherthe attapulgite has a permeability in the range of 0.04-0.07 darcy or0.04-0.19 darcy or 1-3 darcy or 1.5-3 darcy.
 3. The product of claim 1,wherein the metal includes calcium, magnesium, potassium, copper, oriron.
 4. The product of claim 3, wherein the product has a removalefficiency in the oil for peroxide of 50% to 100%.
 5. The product ofclaim 3, wherein the product has a removal efficiency in the oil forchlorophyll of 50% to 100%.
 6. The product of claim 3, wherein theproduct has a bleaching efficiency in the oil for Lovibond red of 65% to100%.
 7. The product of claim 1, wherein the product has the removalefficiency in the oil for phosphorus of 50% to 100% that leaves lessthan 2 ppm phosphorus content in the oil, wherein the product has theremoval efficiency in the oil for the metal of 50% to 100% that leavesless than 10 ppm total metal content in the oil.
 8. The product of claim3, wherein the attapulgite that has been thermally activated has aporosity of 70-85% and/or a pore volume of 1-2 mL/g.
 9. The product ofclaim 8, wherein the attapulgite that has been thermally activated has ad₉₀ of 65-95 μm.
 10. The product of claim 3, wherein the product hasintrinsic pores in the range of 17-30 nm and/or inter pores in the rangeof 2-32 microns.
 11. A method for treating an oil, the methodcomprising: contacting for a contact time the oil with a productcomprising attapulgite, the contact time in the range 4-35 minutes,wherein the attapulgite has been thermally activated, wherein theproduct is free of residual acid; and separating the product from theoil to recover a treated oil, wherein the treated oil has a lower amountof phosphorus than the oil had prior to the contacting and has a loweramount of a metal than the oil has prior to the contacting, whereinfurther the treated oil has: less than 2 parts per million of phosphorusor less than 0.5 ppm of phosphorus, and (b) less than 2 parts permillion of the metal or less than 0.5 ppm of the metal; wherein theproduct has a permeability in oil in the range of 0.04-3 darcy, whereinthe oil comprises a feedstock oil for hydrotreated vegetable oil (HVO)or renewable diesel.
 12. The method of claim 11, wherein the metalincludes calcium, magnesium, potassium, copper, or iron.
 13. The methodof claim 11, wherein the metal is calcium.
 14. The method of claim 11,wherein the treated oil has a lower amount of peroxide than the oil hadprior to the contacting, wherein further the treated oil has 1-3 meq/kgperoxide value.
 15. The method of claim 11, wherein the treated oil hasa lower amount of chlorophyll than the oil had prior to the contacting,wherein further the treated oil has 0-0.1 parts per million (ppm) ofchlorophyll.
 16. The method of claim 11, wherein the treated oil has alower red color than the oil had prior to the contacting.
 17. The methodof claim 16, wherein the red color is a Lovibond red and the product hasa bleaching efficiency of 50% to 99% for Lovibond red.
 18. The method ofclaim 11, wherein the product has a permeability in oil in the range of0.04-0.19 darcy or 1.5-3 darcy or 2-3 darcy.
 19. The method of claim 11,in which the contacting is at a temperature of 80-125° C.
 20. Ableaching clay product comprising: attapulgite, wherein the attapulgitehas been thermally activated, wherein the bleaching clay product has apermeability in oil in the range of more than 0.07 to 0.19 darcy,wherein the bleaching clay product has a surface area of 45-140 m²/g or80-140 m²/g.
 21. The bleaching clay product of claim 20, wherein thebleaching clay product is acid-free.